Sheet metal drawing press



Feb. 28, 1933. F. J..RODE

SHEET METAL DRAWING PRESS- Filed June 10, 1932 2 Sheets-Sheet l Feb. 28, 1933.

F. J. RODE SHEET IETAL DRAWING PRESS 2 SheetS-Sheet 2 Filed June 10, 1932 1 MQQ llll'l'llf'llllllllll-l Patented Feb. 28, 1933 UNITED STA ES PATENT OFFICE FRIDBICH I. BODE, OF CHICAGO, ILLINOIS SHEET IETAL ,DRAWING PRESS Application filed June 10,

the work while the latter is being formed by the dies.

It has been customary to rovide a resiliently yielding cushion, embo ying a pressure pad, operating u on the work holder to cause the material to gripped or clamped with sufiicient pressureto permit the material to flow during the shaping operation, and at o the same time prevent the work from wrinklin but not with suflicient pressure which won (1 cause the material to become ruptured in the shaping operation.

It has been found that for various reasons and at times, such for instance, if the die is not arranged centrally of the base, or when it is desired to perform one operation on one side of the center of the base, in which the blank or work holder is necessary, and an other and different operation .on the other side of the center where the blank holder is not necessary, unequal pressures will be ex,-

erted upon different parts of the pressure ad, with the result that there is a tendenc or the pressure pad, as well as the work hol er to tilt, causing the work to be gri pad with unequal force at different points 0 the work holder, which is not desirable for obvious reasons.

It is one of the objects of the present in vention to provide improved means for maintaining the pressure pad and the blank or work holder a ainst a tilting movement under the stress 0 the operation of the ram 45 upon the work, and to maintain a uniform pressure or gripping of the blank or work holder throughout the entire area thereof.

A further object is to provide improved means operatively associated with the blank 0 or work holder and the pressure pad, which will, when one portion of the, holder or pad 1932. Serial No. 818,871.

is depressed, cause the remaining portions thereof to be correspondingly depressed and thereby maintain the pressure pad as well as the blank holder in a level or horizontal position.

To the attainment of these ends and the accomplishment of other new and useful objects as will appear, the invention consists in the features of novelty in substantially the construction, combination and arrangement of the several parts, hereinafter more fully described and claimed and shownin the vention and in whch Figure 1 is a view partly in elevation, part- .ly in section, with parts broken away and with parts omitted, of a press of this character constructed in accordance with the principles of this invention.

Figure 2 is a view taken on line 2-2, Figure 1, with parts broken away. Figure 3 is a detail sectional view taken on line 3-3, Figure 2.

-Referring more particularly to the drawings the numeral designates generally the base of a press,- having uprights 11 and provided with a ram 12 which is reciprocated in guides 13 on the uprights 11 by means of links 14 connected to the source of power. Carried by the ram is a die 15 and arranged within the base 10'of the press is a cushiomn device, preferably in the form of a close chamber 16 having tubular members 17 r0- jecting thereinto and reciprocable in ese tubular members are pistons 18 upon which a pressure pad 19 located below the bed or olster plate 20 of the press rests; Secured to the bed of the press is a die 21 with which the die carried by the ram '12 co-operates and encompassing the die 21 is a blank or work holder 22 supported by means of pins 23 which pass loosely through the bed plate 20 and engage and rest upon the pressure pad 19. Fluid pressure in the chamber 16 tends normally to hold the pressure. pad 19 against the lower face of the bolster or bed plate 20,

causing the upper surface of the blank or recessed as'at 25 so that the be supported upon the die and the work holder. a

All of the above referred to parts are of the ordinary and well known construction.

It has been found that in many instances when the ram 12 is lowered to contact with the work 24 and as the work holder co-o erates with the die 15 to clamp the work w ile the latter is being formed or shaped, there is an unequal pressure at different points about the area of the blank or work holder as the latter is depressed to lower the pressure pad 19 against the fluid pressure in the chamer 16. This unequal pressure causes the blank or work holder 20 to tilt and this tilting movement will be imparted to the pressure pad 19, with the result that unequal gripping pressure will be exerted upon the work.

Even though such a tiltin movement of the pressure ad and the blan or work holder ma be 0 small degree, the same would be ObjGCtlOIlflblG and would be suific'ient to cause injury to the work.

In the present invention means have been provided for overcoming or preventing such tilting movement and such means operates in a manner that when one portion of the blank or work holder 22 or pad 19 is depressed such movement will cause the remaining portions of the blank or work holder to be correspondingly depressed.

To that end the bed of the press may be pressure pad 19 ma move therein.

rranged alon the end walls of the recess are racks 26 whic are laterally spaced from each other for any suitable distance, and any number of these racks may be provided.

Arranged along the front and rear walls of the recess are racks 27, any suitable number of which may be provided on each of the walls and are laterally spaced from each other.

J ournaled in suitable bearings 28 carried by the pressure pad and arranged therebelovv so as to extend across the ends of the pressure pad are shafts 29 secured to each of which are gears 30 which mesh with the respective racks 26.

J ournaled also in suitable bearings 31, which latter may if desired be ortions of the bearings 28, and extending a on the front and rear edges of the pressure pa and there below are shafts 32, and secured to these shafts 32 are gear wheels 33 which are arranged adjacent and mesh with the respective racks 27.

The shafts 29 and 32 are so arran ed that they will not interfere with each ot erand are also so arranged that they will not interfere with the operation of the pistons 18, as portions of the pistons may, if desired, be cut away so as to accommodate the shafts 32.

lVith this improved construction it will be manifest that no matter at what point pressure from the ram may be applied to either the blank or work holder 22 or the pressure pad 19, the pressure pad 19 will be maintained in a horizontal or level position for the reason that even though the pressure is applied to the pad adjacent one edge or one side thereof, the pressure pad will be lowered and this lowering movement will cause the gears to move over the respective racks and as the gears are operatively connected to the respective shafts, the rotation of the shaft will cause each of the gears to move an equal distance over the respective racks thereby 01perating to pull down the portion of t e pressure pad which is remote from the point at which the pressure of the ram is applied.-

In other words, no matter where the pressure is applied to the pressure pad to force it down,- the gears and racks will cause the pressure pad to always be maintained in a horizontal position and each portion of the ad will move an equal distance under the orce or pressure exerted thereupon by the ram.

As soon as the ram starts to recede the fluid pressure in the chamber 16 will operate upon the pistons 18 to move the pressure pad 19 together with the work or blank holder 22 back to their normal position, the gears moving over the respective racks to permit of such return movement.

While the preferred form of the invention has been herein shown and described, it is to be understood that various changes may be made in the details of construction and in the combination and arrangement of the several parts, within the scope of the claims, without departing from the spirit of this invention.

What is claimed as new is 1. In a press, a reciprocable ram, a fixed die, a work holder, means embodying a pressure pad for yieldingly resisting the movement of the work holder in one direction, and means connected with said pad and operating when pressure is exerted upon one portion of the pad to move it against said resisting means, to cause another portion of the pad to be correspondingly moved to maintain the pad agalnst tilting.

2. In a press, a die, a work holder, means for moving the work holder, means for yieldingly resisting the movement of the work holder in one direction and embodying a pressure pad, and means whereby when one side of the pad is lowered, the other side of the pad will tend to aright itself with the depressed portion, and the pad will be maintained against tilting.

3. In a press, a pressure pad adapted to be moved in one direction by pressure exerted thereupon by the ram of the press, and means operating automatically when pressure is exerted upon the pad on one side of the center 1 correspondingly moved and the pad will aright itself and will be maintained against tiltln 4. n a press, a pressure pad adapted to be lowered during the operation of the press, and gear and rack connections between the pad and bed of the press whereby when pressure is exerted upon one portion of the pad to lower the same another ortion of the pad remote from the point 0 greatest pressure will be correspondingly lowered to maintain the pad against tilting. I I 5. In a press, a pressure pad adapted to be lowered during the operation of the press, and gear and rack connections betweencthe pad and bed of the press whereby when 'pre's' sure is exerted upon one portion of the pad to lower the same another portion of the pad remote from the point of greatest pressure will be correspondingly lowered to maintain the pad against tilting, said gear and rack connections being housed within the bed of the press. I, 6. In a press, a during the operation-of the press, spaced gears carried by the pad below the surface thereof, and spaced racks secured to the press frame and overwhich racks the respective gears move, said gears and racks operating to maintain the pad. against tilting during its movement under pressure, regardless of the point'or area of the application of such pressure upon the pad.

pad adapted to be lowered I gears carried by and arranged along the ends of the pad, spaced gears carried by and arranged along the front and rear edges of the pad, and upright stationary racks secured to stationar partsof the press and over which racks sai gears move.

In testimony whereof I have signed my name to this specification, on this 16th day of May, A. D. 1932. w

' FREDRICH J. RODE.

In a press, a pad adapted to be lowered I during the operation of the press, and means operating automatically to maintain said pad against tilting during its movement under pressure regardless of the oint or area at which said pressure is applie to said pad.

8. In a press, a pad adapted to be lowered during the operation of the press, and positively operating means operatin auto matically to maintain said pad agalnst tilting during its movement under pressure regardless of the point or area at which said pressure is applied to said pad.-

9. In a press, a pressure padadapted to be lowered during the operation of the press by pressure exerted thereupon, and means operating automatically to neutralize any tendency of the pad to tilt during its movement under such pressure, regardless of the point or area of such pad at which such pressure is applied.

10. In a press, a pressure pad adapted to be lowered during the operation of the press by pressure exerted thereupon, and means operating automatically to neutralize any tendency of the pad to tilt during its move ment under such pressure, regardless of the point or area of such pad at which such pres sure is applied, said means embodying gear a. E i 

